1. Field of the Invention
The present invention relates to an imaging device recording, on a recording medium, a still image captured as image information and an image signal processing method of the imaging device. The present invention also relates to a computer program to be executed by the imaging device.
2. Description of the Related Art
Imaging devices such as digital still cameras are now in widespread use. Such an imaging device records still image data obtained from a captured image onto a recording medium during photographing.
When a photographing operation is performed, an actually taken picture often shows that the shutter release timing slips from the best timing of photo opportunity. This is particularly true when a subject is moving. One of the reasons for the timing difference is that it takes time for humans to take action in response to sensing the photo opportunity. Since the imaging device is operated by the human operator, missing the photo opportunity due to release timing delay is unavoidable.
Japanese Unexamined Patent Application Publications Nos. 5-328279 and 10-257365 disclose imaging devices such as digital still cameras that prevent photo opportunity timing slip by taking a predetermined number of images prior to a shutter release operation timing. Such a photo opportunity slip prevention function causes the imaging device to take and record pictures prior to the shutter release operation. Even when the shutter release operation is untriggered, a predetermined number of images of captured still image data is stored on a memory. It is highly likely that the recorded still image data, namely, photographs contain an image the user has intended to take. This arrangement frees the user from missing the photo opportunity due to shutter timing slip.